Coating dies



' July 2, 1968 R. P. woon 3,390,662

COATING DIES Filed March 2. 1966 Arrow/ys United States Patent O 3,390,662 COA'IING DIES Richard P. Wood, Granville, hio, assigner to Owens-Corning Fiberglas Corporation, a corporation of Delaware Filed Mar. 2, 1966, Ser. No. 531,268 15 Claims. (Cl. 11S-125) ABSTRACT F THE DISCLOSURE A coating die having an elastic body with a passageway extending therethrough and means for twisting the body to modify the cross-sectional size of the passageway.

The present invention is directed to a coating die, and more particularly to a die which is capable of varying its effective die passage to desired diameters employed to coat strands, yarns7 rovings and various other types of strands of glass fibers, natural or other synthetic fibers, in addition to monofilaments such as wire and longitudinal tapered elements.

The ability to closely control thickness, and hence weight, of coating material covering strands and the like is highly desirable from both a technical and economy standpoint. One cannot always, however, calculate in advance the die passage diameter required to accomplish a desired coating result. There are many variables which iniluence coating, such as the particular characteristics of a coating material, variations in its viscosity and particular pickup characteristics of a strand to be coated.

Conventional fixed diameter dies may cause difficulties and for many applications are limited in their use. When they are employed in a coating process, attainment of a desired coating result may require use of more than one die. Change from a die of one diameter to one of another diameter is time consuming and interrupts the process. Further, there are times when a uniform coating is desired to be applied over irregular shapes or tapered shapes. Moreover, varying thickness of a coating along the length of strands, yarns and monoiilaments, etc., are at times desired. Conventional fixed diameter passage dies cannot accomplish these types of coatings. The die of the present invention is, however, admirably suited to obtain excellent coating results in a wide variety of these applications.

An object of the present invention is to provide a die which overcomes the difficulties enumerated hereinabove by being adjustable to controlled variations in effective passage diameter.

Another object of the invention is to provide a die having an adjustable diameter passage to correct for die passage wear.

Still another object of the invention is to provide a die which is easily threaded lby reason of its large passage diameter during threading, yet capable of reduced effective passage diameter during operation.

A further object is to provide a die capable of being adjusted in diameter while strands are continuing to be passed therethrough, thereby permitting adjustments in the diameter of the coatings on the strands without interruption in the operations.

The objects are attained using any suitably shaped die body fabricated from elastic or elastomeric material having at least one portion thereof which is a zone of reduced cross sectional area so that the body may be twisted or wrung in the reduced cross sectional area Zone by rotation of one orboth portions of the body located on opposite ends of the zone. In other words, the body portions located on opposite ends of the zone rotate relative to each other. Twisting imparts stresses, which by reason of the reduced amount of body material becomes concentrated in the zone. This, in a sense, causes a choking of that portion of the die passage extending through the reduced cross sectional area zone. The greater the twist applied, the smaller the restricted portion of the passage becomes. Thus, the diameter of the die passage within the zone, the effective passage diameter, can be closely controlled by the amount of twist imparted.

Other objects and advantages of the invention will become apparent as the invention is hereinafter described in more detail with reference made to the accompanying drawings in which:

FIG. l is a perspective View of a die body incorporating the principles of the present invention.

FIG. 2 is a longitudinal cross section view of the die body illustrated in FIG. 1.

FIG. 3 is a rear elevation view of apparatus incorporating and adapted to twist the die body of FIG. 1.

FIG. 4 is a side elevation view of the apparatus shown in FIG. 3.

FIG. 5 is a longitudinal cross section view of the die body of FIG. l and apparatus of FIGURES 3 and 4 showing one way in which coating material might be supplied to the die body for coating a strand.

FIG. 6 is a perspective View of a modified die twisting apparatus incorporating a die body of the invention like that shown in FIG. 1.

FIG. 7 is a side elevation view of the apparatus shown in FIG. 6.

FIG. 8 is a longitudinal cross section view of a modified die body incorporating the principles of the present invention.

Referring to FIGURES l and 2, the die body of the present invention employs a zone of smaller cross section than die body portions adjacent zone ends. The zone extends along the length of a passage which runs through each die body. The zone may be any shape, such as a cylinder or the like, just so long as the zone is of smaller cross section than die body portions adjacent its ends.

FIGURES l and 2 illustrate a preferred embodiment of the invention using a one piece die body 10 fabricated from suitable elastic or elastomeric material such as polyurethane and having generally the shape of a dumbbell. Larger end regions 12 and 14 are squat cylinders in form. External end faces 24 and 26 of end regions 12 and 14 respectively may be flat surfaces or be fashioned with counterbored areas 28 and 29 or the like. A central zone 16 of reduced cross sectional area extends from opposing internal faces 18 and 20 of larger end regions 12 and 14 respectively. Zone 16 comprises a longitudinal arcuate surface extending away from opposing faces IS and 20 at a maximum cross sectional area and proceeding in ever decreasing cross section to a central constituent portion of a minimum cross section. Die bodies fabricated using varying maximum and minimum cross sections may be employed to obtain desired die operating characteristics.

A longitudinal passage 22 extends through the length of body 10. Passage 22 may open onto hat surfaces of external faces 24 and 26 or into counterbored areas 2S and 29 if counterbored areas are provided. While not essential, improved operation results when passage 2.2 extends along the longitudinal axis of body 10, and is preferred. Passage 22 is constructed using any suitable diameter. The diameter may be varied along with dimensions of central zone 16 to accomplish various desired die operating characteristics on large or smaller diameter strands and the like.

Referring to FIGURES 3 and 4, the end regions of die body 1i) are held in suitable die body twisting apparatus which is employed to twist central zone 16 of reduced cross section. The apparatus operates to rotate one end region in relation to the other by holding one end region stationary yet permitting the other end region to rotate. While apparatus may be employed which permits rotation of both ends, apparatus providing rotation of one end is preferred in actual operation.

Prior to being mounted in the twisting apparatus, however, the end to be rotated, eg. end region 12, is inserted into a journal tube fit) in snug fit relation and bonded or otherwise appropriately secured therein. Preferably, the length of tube 4t) is the same is that of the end region secured therein so that external faces are ush with the ends thereof.

Die twisting apparatus shown in FGURES 3 and 4 comprise several elements on a base 32. These elements comprise a forward upstanding housing 31, yokes 50 and 52 and an after opstanding housing 30.

Forward upstanding housing 31 is designed to hold one end region, e.g. end region 14, stationary. While housing 31 is shown generally as a cube, it may be of any suitable shape. Housing 31 has constructed therethrough an opening of suitable size to accept an end region in snug tit relation. Such end region is bonded or otherwise suitably secured therein and is held stationary. Housing 31 stands rigidly secured to base 32.

After housing 36 rotatably holds journal tube 40 and the end region held therein, e.g. region 12. Housing 30 is at a distance from housing 31 equal to the length of the reduced cross sectional area portion and is secured to the base 32. While housing is depicted generally as a cube, any suitable shape may be used. Housing 30 is constructed with an opening therethrough and in which tube 4t) is rotatably held. Additionally, one side of housing 30 contains a threaded opening extending transverse to tube 4t) and into which a set `screw 34 is threaded so that one end thereof may be advanced to press against a portion of the length of tube 40, thereby permitting tube 4t) to be securely held in a rotated position during coat- 4ing operations. Tube 40 is free to rotate through 360 degrees in either direction as many times as is required to obtain a desired die operation; however, die bodies may be employed which have dimensions requiring less than one revolution to obtain desired effective passage diameters.

End surface 41 of tube 40 has holes 42 and 42 for use with a span wrench or other appropriate rotating device to turn tube 4t) to desired rotated positions. Further, end surface 41 has an indicator mark 44 thereon which matches against scale marks appearing on the external face 43 of housing 30. Indicator 44 and scale marks cooperate to show an amount of rotation given to tube 40.

While die body 10 operates well allowing unrestricted horizontal movement or tube within housing 30, a preferred embodiment employs retaining means to preclude horizontal movement of tube 49. Interjected between housings 39 and 31 are yoke elements 50 and 52 which are in abutting relationship with internal opposing faces 43 and 49 of housings 30 and 31 respectively. Yoke 52 is positioned on base 32 with the arcuate portion thereof disposed upwardly and is secured thereto. Yoke is positioned directly above yoke 52 and is secured to housing 31. Yoke 5t) has its arcuate portion disposed downwardly. Hence, the arcuate surfaces of yokes 50 and 52 describe a portion of a circle circumscribing reduced area portion 16 and having a slightly smaller diameter than the outside diameter of tube 40. Yokes 50 and 52 prevent horizontal movement of tube 40, and the end region held therein, along the longitudinal axis of die body 1t).

Referring now to FIGURES 3 and 5, die body 10 is readied for operation 'by threading a strand 60 or the like through passage 22 prior to subjecting central portion 16 to stress by rotating end region 12.

A desired effective passage diameter may be obtained by rotating tube 4t?. A span wrench or any other suitable device is inserted into holes 42 and 42 and turned to rotate tube 4t) until a desired etfective die passage diameter of body 1t) is attained. Tube 4t? is locked in desired position by advancing set screw 34 tightly thereagainst. Because end region 12 is secured within tube 4t), rotation of tube 40 also rotates end region 12 relative to end region 14, which is held stationary by housing 31. Rotation causes a twisting of the central zone 16, which induces a concentration of stresses within the zone material. Thus, in a sense, a portion of passage 22 is choked or constricted to reduce its diameter of passage 22 in zone 16.

Coating material 64 is applied to strand 60 at or before its entrance into passage 22. As shown in FIGURE 5, strand 60 is pulled through passage 22 from right to left. Coating material such as polyvinyl chloride or the like may be used. Further, any fluid suitable for either coating or impregnating strands may be employed with the die of the invention. Moreover, any appropriate coating method may be used, such as conventional strand dipping accomplished prior to strand 60 entering passage 22. Excess coating material may drop into an appropriate collection means (not shown).

FIGURES 6 and 7 illustrate modified die twisting apparatus capable of use with die body 10 permitting rotation of one die body end region. The apparatus allows controlled horizontal movement of the rotatably mounted die body end region along the longitudinal axis of die body 10 as the end region is rotated. Prior to mounting in the twisting apparatus, however, the end region, e.g. end region 12, is inserted into a tube having outside threads thereon and is bonded or otherwise appropriately secured therein. Threads on tube 110 permit threading thereon of a nut 116, operation of which is hereinafter described. Furthermore, end surface 113 of tube 110 has holes 112 and 112 therein suitable for use with a span wrench or the like.

Forward housing 102 maintains end region 14 in a stationary manner as -described hereinabove regarding housing 31. Further, it is secured to base 104 in the same manner as housing 31 is secured to base 32.

After housing 1% holds end region 12 so that it may both rotate and move horizontally along the longitudinal axis of die body 10. Housing 10G is located at a distance from housing 102 somewhat greater than the length of central reduced cross sectional area zone 16 so as to allow room for proper operation of tube 110 and nut 116. While its shape is generally that of a cube, any suitable shape may 'be employed. Moreover, housing 100 is constructed with a threaded opening 117 extending therethrough and into which tube 110 is threaded. Thus, when tube 110 is rotated, it is moved horizontally by the threads of tube 110 in the threads of opening 117.

The desired etfective passage diameter of die passage 22 is attained rotating tube 110i. A span wrench or other suitable device is inserted into holes 112 and 112 to rotate tube 110. Tube 110 is rotated until a desired effective passage diameter is obtained and is locked in position by appropriately advancing nut 116 tightly against housing 100. Because an end region is secured within tube 110, e.g. end region 12, rotation of tube 110 also rotates end region 12 relative to end region 14, which is held stationary in housing 162. Furthermore, rotation of tube 110 moves end region 12 along the longitudinal axis of die body 10 as tube 110 is advanced by the meshing threads of tube 110 and opening 117. The horizontal movement of end region 12 along the longitudinal axis of die body 12 acts, in a sense, in cumulative manner to twisting stresses. Greater passage diameter variations may be accomplished with less twisting.

FIGURE 8 illustrates a modified die body. Modified die body 7 0 is fabricated from one piece of suitable elastic or elastomeric material and has two squat cylinder shaped end regions 72 and 74. Further, a squat cylinder shaped portion 76 is located centrally on body 70 and can be either smaller or larger' in diameter than end regions 72 and 74. Central portion 76 is connected to end regions 72 and 74 by small cross sectional area zones 80 and 82 respectively. Regions 72 and 74 are smaller in cross section than portion 76. The shape of portions 80 and 82 are in its preferred embodiment as ldescribed hereinabove regarding reduced cross sectional area zone 16 of die body 10, Zones 80 and 82 may be any suitably shaped reduced cross sectional zone, eg. a cylinder or the like. A longitudinal passage 84 is drilled, or otherwise appropriately constructed, in body 70. Passage 84 extends along the longitudinal axis of the body 70 and opens into counterbored areas 86 and 88, which may be cut in external end faces 85 and 87 of end regions 72 and 74 respectively, or directly onto flat surfaced external end faces 85 and 87 if no counterbored areas are provided. Die passage diameter control occurs at two zones and may be accomplished in two ways. First, one may rotate center portion 76 and hold end regions 72 and 74 stationary. Apparatus similar to that described hereinabove and used to hold and rotate a portion of die body may be used to cause a twisting of the material of sections 80 and 82. Here, however, end regions 72 and 74 are held stationary and portion 76 is rotatably held. Rotation of portion 76 causes modification of the diameter of passage 84 in the portions extending through zones 80 and 82. Secondly, center portion 76 may be held stationary and end regions 72 and 74 may be rotated either together or'separately in the same or opposite ydirections to constrict passage 84. If operated independently, restrictions of different diameters may be obtained in passage 84 extending through zones 80 and 82.

While the invention has been described in connection with coating strands, yarns and monoiilaments such as wire, etc., the invention may be employed to coat longitudinal tapered elements. Coatings of tapered elements may be accomplished by programmed operation of apparatus to twist a die body and thereby vary effective passage diameter in relation to the taper of the longitudinal element to be coated.

Similarly, varying the amount of coating applied to a strand, yarn, monolament or the like may be accomplished to obtain a tapered coating or repeated increase and decrease in material applied along the length thereof. One need only vary the amount of twist imparted to the die body in a predetermined manner as the element to be coated -is passed therethrough.

Thus, it can be seen that the invention as described constitutes an easily used and useful coating device which effectively overcomes difficulties inherent in conventional xed passage dies.

In view of the foregoing, it will be recognized that while particular embodiments of the invention have been shown, many modifications may be made within the concepts of the invention and, therefore, it is not the intent to limit the inventions specific embodiments.

I claim:

1. A coating die comprising a body of elastic material having a passageway extending therethrough for movement therethrough of linear material to be coated, means for holding said body at the opposite ends of said passage, means for rotating the ends of said body in opposite directions relative to each other to establish to a predetermined desired minimum dimension at a zone along its length between the ends of said passage, means for retaining said body in such related position.

2. A coating die comprising a body, said body being made of elastic material, said body having a passage extending therethrough, said body having at least one portion thereof which is a zone of reduced cross sectional area along the length -of said passage, the diameter of said passage varied when said zone is twisted by rotation of die body portions adjacent the opposite ends of said zone in opposite direction relative to each other, mounting `means holding body portions adjacent the opposite ends of said zone, said mounting means providing rotation of die body portions adjacent to the opposite ends of said zone.

3. A coating die recited in claim 2 in which said zone of reduced cross sectional area has a constituent zone of minimum cross section.

4. A coating die comprising a longitudinal one piece die body, said die body being made of elastic material, said die body having a passage extending the length thereof, said die body having at least one portion thereof which is a zone of reduced cross sectional area intermediate the ends, mounting means supporting die body portions adjacent the opposite ends of said zone, said mounting means providing rotation of die body portions adjacent to the opposite ends of said zone in opposite directions relative to each other thereby twisting said zone to modify the diameter of the passage extending through said zone, means to maintain said zone in twisted condition.

5. A coating die comprising a longitudinal one piece die body, said die body being made of elastic material, said die body having a passage extending the length thereof, said die body having one portion thereof which is a Zone of reduced cross sectional area intermediate the ends, mounting means rotatably holding one end of said die body, mounting means stationarily holding the other end of said die body, said zone being twisted when the rotatably mounted end of said die body is turned thereby modifying a portion of the passage extending through sa-id zone, means to maintain said Zone in a twisted condition.

6. A coating die as recited in claim 5 in which said zone of reduced cross section has a constituent zone of minimum cross section.

7. A coating die comprising a longitudinal die body, said die body being made of elastic material, said die body extending the length thereof, said die body having two portions thereof which are zones of reduced cross sectional area intermediate the ends thereof, said zones in spaced apart relation along the length of said die body, mounting means supporting die body portions adjacent opposite ends of said zones, said mounting means providing rotation of die body portions adjacent to the opposite ends of said zones in opposite directions relative to each other thereby twisting said zones to modify the diameter of the portion of the passage extending through said zone, means to maintain said Zone in twisted condition.

8. A coating die recited in claim 7 in which said zone of reduced cross section has a constituent zone of minimum cross section.

9. A coating die comprising a longitudinal one piece die body, said die body being made of elastic material, said die body having a passage extending the length thereof, said die body comprising cylindrical end regions and a central portion which is a Zone of reduced cross sectional area, mounting means supporting said cylindrical end regions, said mounting means providing rotation of said cylindrical end regions in opposite directions relative to each other thereby twisting said zone to modify the diameter of the portion of the passage extending through said zone, means to maintain said zone in a twisted condition.

10. A coating die recited in claim 9 in which sa-id zone of 'reduced cross section has a constituent zone of minimum cross section.

11. A coating die comprising a body of elastic material having a passageway extending therethrough for movement of linear material to be coated, said body being generally of cylindrical shape, a section of reduced crosssectional dimension being provided in said body between the ends of said passageway, means for holding said body at the opposite ends of said passageway, means for rotating the ends of said body at the opposite ends of said body in opposite directions relative to each other to establish a predetermined desired minimum dimension along its length, means for retaining said body in such rotated position.

12. A die for linear `material comprising a body of elastic material having a passageway for movement of linear material therethrough, means for twisting said body to modify the cross-sectional area of the passageway at a zone between the ends of the passageway.

13. A die according to claim 12 where there is in said body a' section of reduced cross-sectional dimension between the ends of said passageway.

14. A die according to claim 12 further including means for twisting said body at a rate to modify the cross-sectional area of the passageway in said zone in a predetermined mlanner as said linear material moves through the passageway.

` l5. A die comprising a body, said body being made of elastic material, said body having a passageway extending therethrough, said body having at least one portion thereof which is a zone of reduced cross-sectional area surrounding said passageway between the ends of said passageway, the diameter of said passageway being varied in the vicinity of said zone when said body is twisted by rotation of die body portions adjacent the opposite sides of said zone in opposite directions relative to each other, mounting means holding body portions adjacent the opposite sides of said zone, said mounting means providing rotation of die body portions adjacent to the opposite sides of said zone.

References Cited UNITED STATES PATENTS 2,341,450 2/1944 Knaus 118-405 2,657,414 11/1953 Miller et al. 15-2102 3,032,812 5/1962 Van Riper 15-2l0.2

CHARLES A. WILLMUTH, Primary Examiner.

R. I. SMITH, Examiner. 

